Modern technologies are developing prosperously. Most electronic devices, for example, indoor telephones, fax machines, printers, mobile phones, tablet computers, and billboards, include a display. Because the text and images shown in color are pleasing to the eye, color displaying has become the mainstream in the development of display technology. Nonetheless, some electronic devices still adopt black-and-white/grayscale displaying method for displaying text or image information presently. Color displaying is the current mainstream, thereby the demand for color displays is huge. The manufacturing technology of color displays has improved substantially in the present day. Thanks to mass production, the manufacturing cost of color displays has reduced, lowering their street price accordingly. Compared with color displays, black-and-white/grayscale displays have fewer market demands. Thereby, the prices of black-and-white/grayscale displays are higher than those of color displays.
Based on the reasons as described above and the consideration for costs, many electronic manufacturers hope to change the black-and-white/grayscale displays on electronic devices to color ones for displaying black-and-white/gray scale images as well. Nonetheless, the microcontrollers of some electronic devices are low-end microprocessors with limited transmission capability only affordable for transmitting black-and-white/grayscale image data having small data quantity. Low-end microprocessors need longer time for transmitting color image data having large data quantity. For color displays, the transmission rate for color image data by low-end microprocessors is too slow, leading to slow image displaying rate and inferior displaying quality. In order to solve the problem, low-end microprocessors should be replaced by high-end ones, which further increases the overall cost of electronic devices.
Accordingly, the present invention provides a driving circuit, which receives black-and-white/grayscale input data and produces color output data according the black-and-white/grayscale input data for driving a color display to display black-and-white/grayscale images. Thereby, the above problem according to the prior art can be solved.